Amphibian landing gear



Sept. 1, 1936. I I G. LUBURG I 2,053,093 7 AMPHIBIAN LANDING GEAR FiledDec. 9, 1935 2 Sheets-Sheet l IN VEN TOR. GUY A. LUBUE 6.

A TTOR S.

Sept. 1, 1936 G. A. LUBURG AMPHIBIAN LANDING GEAR Filed Dec. 9,-1933 2Sheets-Sheet 2 I INVENTOR. GUY ALUBURQ.

Patented Sept. 1, 1936 LANDING GEAR Guy A. Luburg, Snyder, N. Y.,assignor to Curtis! Aeroplane & Motor Company, Inc., a corporation ofNew York Application December 9, 1933, Serial No. 701,605

2 Claims. (Cl. 244-2 This invention relates to aircraft, and is moreparticularly concerned with improvements in retractable landing gearsfor amphibians.

Generally, the invention provides a wheeled landing gear for a flyingboat or a seaplane, equipped with a boat hull or pontoons, respectively,wherein the major portion of the wheeled landing gear may be retractedwithin recesses formed in the bottom of the flotation body. When soretracted, the aircraft may alight on water. The landing gear maybeextended from its retracted position, so that the wheels are inposition for ground contact, The bottom of the flotation body isespecially arranged to avoid excessive drag in the water when thelanding gear is retracted. As is well known in the art, aircraftflotat-ion bodies are provided with a step intermediate their length,the hull bottoms fore and aft of the step slanting at an obtuse anglefrom each other. In my invention, I provide an auxiliary step forward ofthe main step. and locate the recesses for the wheeled landing gear inthe bottom portion intermediate the auxiliary and main steps. By thisconstruction, the wheeled landing gear is longtudinally located forwardof the center of gravity of the aircraft, while the main step is, as isthe usual practice, located below or only slightly aft of the center ofgravity of the aircraft. The auxiliary step ahead of the wheeled landinggear assists the action of rising to the main step when the aircraft istaking off. When the aircraft has risen to plane upon the main step, theforward portion of the hull is principally out of water, and theauxiliary step then becomes inactive. Sufficient smooth bottom area isprovided between the wheel recesses and the main step so that properplaning and flotation action will take place when the aircraft isplaning on the main step, prior to and up to take-oil? speeds.

It is an object of the invention, therefore, to

.provide an amphibian landing gear wherein the landing wheels may beretracted into recesses in the bottom of the flotation body.

A further object is to provide recesses for a wheeled landing gearforward of the main step of the flotation body.

A further object is to provide an auxiliary step in the flotation bodyforward of the main step.

gear tread is of considerable magnitude with relation to the width ofthe flotation body.

Another object is to provide a wheeled landing A still further object isto provide means for extending and retracting a wheeled landing gearfrom and within a water flotation body.

Further objects will be apparent from a reading of the subjoinedspecification and claims and from a consideration of the drawings, inwhich similar numbers indicate similar parts, and in which:

Fig. 1 is a side elevation of an aircraft pontoon embodying theinvention;

Fig. 2 is an enlarged fragmentary side elevation of that portion of thepontoon by which the Wheeled landing gear is carried, showing also indotted lines, certain of the structure of the wheeled landing gear;

Fig. 3 is a front elevation of the pontoon, showing the wheeled landinggear in extended and retracted positions; and r Fig. 4 is a section onthe line 4-4 of Fig. 3.

An aircraft pontoon I 0, of otherwise well known and conventionaldesign, is provided with a main step i l intermediate the pontoon lengthand dividing the pontoon bottom I! into a rearward portion l3 and aforward portion I, the step being located, as is the usual practice,below and slightly aft of the airplane center of gravity. An auxiliarystep l5 divides the bottom forwardly of the main step II to provide anintermediate bottom portion l6. Generally speaking, the intermediateportion l6 and the forward portion H of the bottom, are in substantiallyparallel planes. In the intermediate portion ii, a. circular recess i1is formed on each side of the plane'of symmetry of the pontoon ill. Itis understood that the pontoon I0 is of conventional V-bottomconstruction, as shown in Fig. 3, and that duplicate recesses I! areprovided on each side of th plane of symmetry of the pontoon. is

From the upper deck of the pontoon, rigid truts I8 extend laterally tohold a bearing l9 laterally spaced from the pontoon. On this bearing l9is carried a strut 20 which may be a shock absorbing strut ofconventional form comprising a plunger 2l slidable against suitablesprings, compressed air or other resilient 'triedia, within acylindrical portion 22. A fitting 2 t at the bottom of the strut 20carries an axle 24 on which a wheel 25 is carried for rotation. Thefitting 23 is also provided with an inboard pivot 26, on which ismounted a strut framework 21 extending inwardly to support, at itsinner-end, rollers 28. For longitudinally bracing the landing gearagainst landing shocks, these rollers 28 are longitudinally spaced andengage in longitudinally spaced guideways 29 within the pontoonstructure. extend upwardly within the pontoon, and means 30 are providedto translate the rollers 28. with the struts 21, along the guideways 29so that the landing gear may be extended or retracted. Such I means 30may comprise chains, cables or other devices well known in the art. Itwill thus be seen that, when the rollers 28 are drawn upwardly in theguideways 29, the struts 20 and 21, with the wheel 25, are swung in atransverse plane, to be drawn inwardly and upwardly within the pontoon,so that thewheel 25 nests in the recess II. The relationship of thestruts, wheel and recess is so arranged that the outer surface of thewheel 25, when in its retracted position, lies substantially flush withthe bottom surface 16 of the pontoon. It will be noted that inretracting the landing gear, the whole assembly swings about the bearingl9. The landing-gear may be extended by reversing the travel of therollers 28 in the guideways 29, where'byfthe landing gear is pusheddownwardly and outwardly to occupy a ground contacting position such asis represented by the dotted lines in' Fig. 3, The bearing l9 may be sospaced with'respect to'the aircraft that the tread between the landingwheels when extended is considerably'wider than the width of thepontoon. In their extended position, the shock absorbing struts 20assume a substantially vertical attitude to most e'fliciently assumelanding shocks imposed upon them.

It is to be understood that the specific arrangement of retractingmechanism as shown, may bevaried without detracting from the scope ofthe invention except as limited by the appended claims. For instance,the struts 21 may be organized to buckle for extension or retractionofpontoon, so that the parasite resistance of such wheeled landing gearmay be considerably reduced when the aircraft is in flight.

' It will be seen that the bottom portion it of the pontoon is organizedto present a considerable plane area forward of the step ii, so thatwhen the aircraft is being propelled at speed upon the The guideways 29water, this bottom area will be adequate to support the weight of thecraft. The angular relationship between the bottom portions 16 and I3 issuch that the fore and aft rocking movement of 'the appended claims tocover all such modifications and changes.

- Whatis claimed is:

-1. In an amphibian airplane, in combination, a float provided with aV-bottom and with longitudinally spaced rearwardly facing transverselyextending steps, said bottom, intermediately of said steps, and nearerto the forward step, and at opposite sides of the fore and aft centerline of said V-bottom, having formed therein substantially circularrecesses, retractable landing gear wheels adapted, when extended, tooccupy positions, one each at opposite sides of and well below the floatbottom outboard of the chines thereof, and said wheels, when retracted,being adapted to occupy positions, respectively, within said .recesses,and means to move said wheels from an extended to a retracted positionand vice versa.

2. In an amphibian airplane, in combination, a

float provided with a V-bottom and with longitudinally spaced rearwardlyfacing transversely extending stem, said bottom, intermediately of saidsteps, and nearer to the forward step, and at opposites ides of the foreand aft center line of said V-bottom, having formed therein substan--tially circular recesses, each of which, at its outer edge, is open to atransverse slot formed in the float and extended through and upwardlybeyond the chines thereof,

tions, one each at opposite sides of and well below the float bottomoutboard of said chines, and said wheels,- when retracted, being adaptedto occupy positions, respectively, within said recesses, means carryingsaid wheels and fastened to said float and movable during wheelextension and retraction to passages respectively partly within andwholly without said transverse slots, and means to so move theretractable wheeled landing gear.

GUY A. LUBURG.

retractable landing gear wheels adapted, when extended, tooccupy posi-

